Note: This Code is referenced in clause 32(2)(b) of Ontario Regulation 629/94 (Diving Operations) made under the Occupational Health and Safety Act.

Physician knowledge and competency

This examination shall be conducted by a physician with basic training in diving medicine who is capable of screening workers for exposure to changes in ambient pressure. The physician shall:

  1. have an active license to practice medicine
    1. in Ontario if the examination occurs in Ontario, or
    2. in their home jurisdiction within Canada or the United States if the examination occurs in the jurisdiction where they are licensed to practice
  2. have completed a basic training course in diving medicine
  3. have an effective current working knowledge of the physical laws affecting the diver and the underwater operation through continuing medical education
  4. have an understanding of the interaction that occurs between these physical laws and the diver’s physiology and of the implications of this interaction for the diver
  5. have sufficient awareness of the pathological conditions that can arise as a consequence of exposure to pressure
  6. have the ability to perform a competent physical evaluation of diving candidates, divers and caisson workers
  7. be familiar with the management steps to be followed in the event of an accident or other adverse condition arising as a consequence of diving operations
  8. be knowledgeable with respect to the appropriate steps to be taken in the initial investigation of any diving incidents, accidents, or fatalities

Purpose

The objective of the medical examination is to protect the health of divers by:

  1. identifying pre-existing health conditions that could be aggravated by exposure to changes in ambient pressure (compression and decompression)
  2. evaluating the effect of changes in ambient pressure on divers
  3. enabling remedial action to be taken when necessary to ensure the safety of the diver
  4. providing health education on the effects of changes in ambient pressure and on the results of the medical examination

Medical examination

The medical examination shall consist of the following elements:

  • medical, occupational and family history
  • physical examination
  • clinical tests
  • determination of fitness (fitness certificate)
  • health education on the effects of changes in ambient pressure and on the results of the medical examination

Medical screening and occupational history

At the medical examination the examining physician shall review the diver's personal log. A screening questionnairefootnote 1 shall be administered at the examination to identify any symptoms or medical conditions that could impact fitness to dive.

An occupational history shall be undertaken to identify:

  1. previous exposure to changes in ambient pressures (both occupational and non-occupational)
  2. history of frequency and duration of exposure to changes in ambient pressure since previous examination
  3. history of signs and symptoms that may indicate prior injury as a result of compression or decompression injury such as middle ear trauma, air embolism, pulmonary barotrauma, decompression sickness, oxygen convulsions, vestibular damage, high pressure neurological syndrome and aseptic bone necrosis

Physical examination

During the physical examination, particular attention shall be directed to those systems that may be affected by changes in ambient pressure and stress involved in diving, for example, cardiopulmonary, ear, nose and throat (ENT), musculoskeletal system and central nervous system.

Clinical tests

Clinical tests aid in the assessment of a diver's fitness for and continued exposure to changes in atmospheric pressure and the stress involved in diving. Test requisition forms must indicate that the patient is a diver and that the purpose of the investigation is to assess medical fitness to dive. This will enable the interpreting physician (e.g., radiologist, internist/cardiologist, or respirologist) to report the test results appropriately.

  1. Blood work
    A complete blood count shall be conducted on the initial examination and with each subsequent diving medical. Other blood work (e.g., sickle cell test) shall be conducted if clinically indicated.
  2. Urinalysis
    Blood, glucose and protein urinalysis shall be conducted on the initial examination and with each subsequent diving medical. Other urinalysis testing shall be conducted if clinically indicated.
  3. Spirometry
    (forced vital capacity (FVC), forced expiratory volume (FEV1), FEV1/FVC ratio, and flow-volume curves) Spirometry shall be undertaken at the initial examination and periodically if clinically indicated. They shall include FVC, FEV1, FEV1/FVC ratio, FEF 25-75%, FEF25, and FEF50 or other equivalent flow rate measurement that could indicate small airways dysfunction or air trapping. Particular attention must be given to indices of flow at low-mid volumes. Values less than 75% of predicted are not necessarily disqualifying but must trigger detailed pulmonary function tests and respirology consultation, perhaps with methacholine challenge testing.
  4. Chest X-rays
    Chest X-rays shall include full-size posteroanterior (PA) (inspiratory and expiratory) and lateral. They shall be conducted on the initial examination and, if clinically indicated, periodically.

  5. Electrocardiogram (with exercise tolerance tests)
    An electrocardiogram (ECG) shall be conducted in accordance with the diver’s age, as follows:

    1. Less than 40 years of age —initial 12 lead resting ECG
    2. At 40 years of age — standardized exercise ECG
    3. Over 40 years of age — resting ECG required every two years to age 50 and
    4. At or over 50 years of age — standardized exercise ECG required annually

    An ECG shall also be conducted as clinically indicated.

  6. Pure tone audiogram
    A pure tone audiogram shall be performed on both ears, 250-8000 Hz inclusive, at least 12 hours after any high noise exposure. This audiogram shall be conducted at the time of initial examination and then periodically every two years. Additional audiograms must be conducted if clinically indicated (e.g., after barotrauma).

Determination of fitness

When making a determination of ‘fit to dive’, ‘fit to dive with limitations’, or ‘unfit to dive’, the examining physician shall inquire about and consider the risks associated with, but not limited to, the following factors:

  1. age
  2. physical fitness
  3. medication and underlying conditions
  4. smoking
  5. disability and functional loss
  6. infection and impaired immunity
  7. obesity
  8. mental health
  9. alcohol, drug or substance use
  10. respiratory system
  11. cardiovascular system
  12. central nervous system
  13. musculoskeletal system
  14. ear, nose and throat
  15. vision
  16. dental health
  17. endocrine system
  18. genitourinary system
  19. gastrointestinal system
  20. skin
  21. haematology

Examining physicians are expected to maintain proficiency with the latest available best practice guidelines on the absolute and relative contraindications to occupational diving, and to further investigate any concerns or risk factors identified in the history and physical examination that may uncover the existence of such contraindications.

Temporary medical restriction

Some temporary medical conditions may be aggravated by exposure to changes in ambient pressure. If they are present, exposure to changes in ambient pressure must be temporarily restricted until the disease or condition has been resolved. This may include, but are not limited to, conditions such as the following:

  1. upper respiratory infections (including otitis media and sinusitis)
  2. lower respiratory infections
  3. barotrauma
  4. decompression sickness
  5. wounds or physical injury (until healed or resolved)
  6. surgery (until healed and physical fitness restored)
  7. pregnancy
  8. minor episodes of head injury or
  9. acute or chronic skin infection
  10. peptic ulcer disease associated with pyloric obstruction or severe reflux
  11. unrepaired abdominal wall hernias at risk of incarceration
  12. prescription of anticoagulant drugs

Fitness certificate

The fitness certificate provided to the diver shall state:

  1. that the diver is fit, fit with limitations or unfit to dive
  2. that the medical examinations were conducted according to the Code for the Medical Examination of Divers, dated July 2025
  3. If the examination is conducted outside of Ontario, the certificate shall
    1. reference any other standard(s) against which the examination was performed; and
    2. that, it meets the requirements outlined in this Code
  4. the date of the examination
  5. the date of the next required examination. Examinations are required:
    1. Every two years if under age 40
    2. Annually if age 40 or older; and
    3. More frequently if recommended by the person’s examining physician
  6. the physician’s name, address and signature
  7. If the examination is conducted outside of Ontario, the certificate shall also include the physician’s license number and jurisdiction where the examination took place and for which they have an active license to practice medicine

Not a required component of the Code

At the discretion of the examining physician, other tests including psychometric testing and psychiatric examination may be undertaken.

Long bone imaging may be indicated in cases of suspected dysbaric osteonecrosis.